Make QGraphicsEffect independent of QGraphicsItem.

This makes it possible to basically implement support for graphics effects
on pretty much everything, e.g. QWidget. We currently only support
effects on QGraphicsItem, but there's more to come :-)

6 files changed, 31 insertions, 35 deletions

diff --git a/examples/graphicsview/blurpicker/blureffect.cpp b/examples/graphicsview/blurpicker/blureffect.cpp
index 6c2095d5c..43791c6fb 100644
--- a/examples/graphicsview/blurpicker/blureffect.cpp
+++ b/examples/graphicsview/blurpicker/blureffect.cpp
@@ -43,28 +43,27 @@
 
 #include <QDebug>
 
-BlurEffect::BlurEffect()
+BlurEffect::BlurEffect(QGraphicsItem *item)
     : QGraphicsBlurEffect()
-    , m_baseLine(200)
+    , m_baseLine(200), item(item)
 {
 }
 
-void BlurEffect::adjustForItem(const QGraphicsItem *item)
+void BlurEffect::adjustForItem()
 {
     qreal y = m_baseLine - item->pos().y();
     qreal radius = qBound(0.0, y / 32, 16.0);
     setBlurRadius(radius);
 }
 
-QRectF BlurEffect::boundingRectFor(const QGraphicsItem *item)
+QRectF BlurEffect::boundingRect() const
 {
-    adjustForItem(item);
-    return QGraphicsBlurEffect::boundingRectFor(item);
+    const_cast<BlurEffect *>(this)->adjustForItem();
+    return QGraphicsBlurEffect::boundingRect();
 }
 
-void BlurEffect::drawItem(QGraphicsItem *item, QPainter *painter,
-                                       const QStyleOptionGraphicsItem *option, QWidget *widget)
+void BlurEffect::draw(QPainter *painter)
 {
-    adjustForItem(item);
-    QGraphicsBlurEffect::drawItem(item, painter, option, widget);
+    adjustForItem();
+    QGraphicsBlurEffect::draw(painter);
 }
diff --git a/examples/graphicsview/blurpicker/blureffect.h b/examples/graphicsview/blurpicker/blureffect.h
index cafd910fa..2aea8bf33 100644
--- a/examples/graphicsview/blurpicker/blureffect.h
+++ b/examples/graphicsview/blurpicker/blureffect.h
@@ -48,21 +48,20 @@
 class BlurEffect: public QGraphicsBlurEffect
 {
 public:
-    BlurEffect();
+    BlurEffect(QGraphicsItem *item);
 
     void setBaseLine(qreal y) { m_baseLine = y; }
 
-    QRectF boundingRectFor(const QGraphicsItem *item);
+    QRectF boundingRect() const;
 
-    void drawItem(QGraphicsItem *item, QPainter *painter,
-                  const QStyleOptionGraphicsItem *option = 0,
-                  QWidget *widget = 0);
+    void draw(QPainter *painter);
 
 private:
-    void adjustForItem(const QGraphicsItem *item);
+    void adjustForItem();
 
 private:
     qreal m_baseLine;
+    QGraphicsItem *item;
 };
 
 #endif // BLUREFFECT_H
diff --git a/examples/graphicsview/blurpicker/blurpicker.cpp b/examples/graphicsview/blurpicker/blurpicker.cpp
index 10ce44fc5..9904dfa68 100644
--- a/examples/graphicsview/blurpicker/blurpicker.cpp
+++ b/examples/graphicsview/blurpicker/blurpicker.cpp
@@ -79,7 +79,7 @@ void BlurPicker::updateIconPositions()
         pos -= QPointF(40, 40);
         icon->setPos(pos);
         baseline = qMax(baseline, ys);
-        static_cast<BlurEffect *>(icon->effect())->setBaseLine(baseline);
+        static_cast<BlurEffect *>(icon->graphicsEffect())->setBaseLine(baseline);
     }
 
     m_scene.update();
@@ -103,7 +103,7 @@ void BlurPicker::setupScene()
         QPixmap pixmap(names[i]);
         QGraphicsPixmapItem *icon = m_scene.addPixmap(pixmap);
         icon->setZValue(1);
-        icon->setGraphicsEffect(new BlurEffect);
+        icon->setGraphicsEffect(new BlurEffect(icon));
         m_icons << icon;
     }
 
diff --git a/examples/graphicsview/lighting/lighting.cpp b/examples/graphicsview/lighting/lighting.cpp
index fff22046d..63f0a6c51 100644
--- a/examples/graphicsview/lighting/lighting.cpp
+++ b/examples/graphicsview/lighting/lighting.cpp
@@ -98,7 +98,7 @@ void Lighting::setupScene()
 
             item->setPen(QPen(Qt::black));
             item->setBrush(QBrush(Qt::white));
-            item->setGraphicsEffect(new ShadowEffect(m_lightSource));
+            item->setGraphicsEffect(new ShadowEffect(item, m_lightSource));
             item->setZValue(1);
             item->setPos(i * 80, j * 80);
             m_scene.addItem(item);
diff --git a/examples/graphicsview/lighting/shadoweffect.cpp b/examples/graphicsview/lighting/shadoweffect.cpp
index c1d384ab1..e2dd8640b 100644
--- a/examples/graphicsview/lighting/shadoweffect.cpp
+++ b/examples/graphicsview/lighting/shadoweffect.cpp
@@ -43,14 +43,14 @@
 
 #include <math.h>
 
-ShadowEffect::ShadowEffect(QGraphicsItem *source)
+ShadowEffect::ShadowEffect(QGraphicsItem *item, QGraphicsItem *source)
     : QGraphicsShadowEffect()
-    , m_lightSource(source)
+    , item(item), m_lightSource(source)
 {
     setBlurRadius(8);
 }
 
-void ShadowEffect::adjustForItem(const QGraphicsItem *item)
+void ShadowEffect::adjustForItem()
 {
     QPointF delta = item->pos() - m_lightSource->pos();
     setShadowOffset(delta.toPoint() / 30);
@@ -61,15 +61,14 @@ void ShadowEffect::adjustForItem(const QGraphicsItem *item)
     setOpacity(qBound(0.4, 1 - dd / 200.0, 0.7));
 }
 
-QRectF ShadowEffect::boundingRectFor(const QGraphicsItem *item)
+QRectF ShadowEffect::boundingRect() const
 {
-    adjustForItem(item);
-    return QGraphicsShadowEffect::boundingRectFor(item);
+    const_cast<ShadowEffect *>(this)->adjustForItem();
+    return QGraphicsShadowEffect::boundingRect();
 }
 
-void ShadowEffect::drawItem(QGraphicsItem *item, QPainter *painter,
-                                       const QStyleOptionGraphicsItem *option, QWidget *widget)
+void ShadowEffect::draw(QPainter *painter)
 {
-    adjustForItem(item);
-    QGraphicsShadowEffect::drawItem(item, painter, option, widget);
+    adjustForItem();
+    QGraphicsShadowEffect::draw(painter);
 }
diff --git a/examples/graphicsview/lighting/shadoweffect.h b/examples/graphicsview/lighting/shadoweffect.h
index 09b63e390..d4aa440de 100644
--- a/examples/graphicsview/lighting/shadoweffect.h
+++ b/examples/graphicsview/lighting/shadoweffect.h
@@ -48,18 +48,17 @@
 class ShadowEffect: public QGraphicsShadowEffect
 {
 public:
-    ShadowEffect(QGraphicsItem *source);
+    ShadowEffect(QGraphicsItem *item, QGraphicsItem *source);
 
-    QRectF boundingRectFor(const QGraphicsItem *item);
+    QRectF boundingRect() const;
 
-    void drawItem(QGraphicsItem *item, QPainter *painter,
-                  const QStyleOptionGraphicsItem *option = 0,
-                  QWidget *widget = 0);
+    void draw(QPainter *painter);
 
 private:
-    void adjustForItem(const QGraphicsItem *item);
+    void adjustForItem();
 
 private:
+    QGraphicsItem *item;
     QGraphicsItem *m_lightSource;
 };